Katharine Steinbeck

The importance of physical activity in the prevention of overweight and obesity in childhood: a review and an opinion

The prevalence of childhood obesity is increasing and there are a number of theoretical reasons as to why intervention may be more effective in childhood. There are certain risk times for the development of obesity in childhood, which provide a basis for targeted intervention. In addition, tracking data supports the persistence of obesity, at least in later childhood, as well as cardiovascular risk factors. Physical activity is the discretionary component of energy expenditure and there is evidence that falling levels of physical activity are contributing to the obesity epidemic. Physical activity in children is related to developmental stage, is reduced with increasing age and is influenced by parental physical activity. While there is debate about the immediate health benefits of physical activity to children, there are data to support that lower physical activity levels and sedentary behaviours are associated with a higher prevalence of obesity in children. Physical activity is an accepted strategy in the treatment of established obesity (tertiary prevention). The role of physical activity in the prevention of obesity (primary and secondary prevention) is less clear. However a number of recent school‐based interventions directed at either increasing physical activity and/or decreasing sedentary behaviours, have shown encouraging results. On balance, increasing physical activity in children is an attractive and non‐restrictive approach to obesity prevention. To adopt this approach requires the support and involvement of many community sectors other than health.

Twelve-Month Effectiveness of a Parent-led, Family-Focused Weight-Management Program for Prepubertal Children: A Randomized, Controlled Trial

BACKGROUND. Parenting-skills training may be an effective age-appropriate child behavior-modification strategy to assist parents in addressing childhood overweight. OBJECTIVE. Our goal was to evaluate the relative effectiveness of parenting-skills training as a key strategy for the treatment of overweight children. DESIGN. The design consisted of an assessor-blinded, randomized, controlled trial involving 111 (64% female) overweight, prepubertal children 6 to 9 years of age randomly assigned to parenting-skills training plus intensive lifestyle education, parenting-skills training alone, or a 12-month wait-listed control. Height, BMI, and waist-circumference z score and metabolic profile were assessed at baseline, 6 months, and 12 months (intention to treat). RESULTS. After 12 months, the BMI z score was reduced by ∼10% with parenting-skills training plus intensive lifestyle education versus ∼5% with parenting-skills training alone or wait-listing for intervention. Waist-circumference z score fell over 12 months in both intervention groups but not in the control group. There was a significant gender effect, with greater reduction in BMI and waist-circumference z scores in boys compared with girls. CONCLUSION. Parenting-skills training combined with promoting a healthy family lifestyle may be an effective approach to weight management in prepubertal children, particularly boys. Future studies should be powered to allow gender subanalysis.

Obesity and Risk of Low Self-esteem: A Statewide Survey of Australian Children.

OBJECTIVE. There is variation in the psychological distress associated with child obesity. Low self-esteem, when observed, provides very little information about the nature of the distress and no indication of the proportion of obese children affected. This study used a domain approach to self-competence to evaluate self-esteem in a representative sample of Australian children. PARTICIPANTS AND METHODS. A total of 2813 children (mean age: 11.3 years) took part in the study. They were recruited from 55 schools and were all in the last 2 years of primary school. Participants completed the Self-perception Profile for Children, a measure of body shape perception, and their height and weight were measured. RESULTS. Obese children had significantly lower perceived athletic competence, physical appearance, and global self-worth than their normal weight peers. Obese girls scored lower in these domains than obese boys and also had reduced perceived social acceptance. Obese children were 2–4 times more likely than their normal weight peers to have low domain competence. In terms of prevalence, 1 of 3 obese boys and 2 of 3 obese girls had low appearance competence, and 10% and 20%, respectively, had low global self-worth. Body dissatisfaction mediated most of the association between BMI and low competence in boys but not in girls. CONCLUSIONS. Obesity impacts the self-perception of children entering adolescence, especially in girls, but in selected areas of competence. Obese children are at particular risk of low perceived competence in sports, physical appearance, and peer engagement. Not all obese children are affected, although the reasons for their resilience are unclear. Quantifying risk of psychological distress alongside biomedical risk should help in arguing for more resources in child obesity treatment.

Comparison of metabolic syndrome prevalence using six different definitions in overweight pre-pubertal children enrolled in a weight management study

Objectives:To assess the implications of variation in Metabolic Syndrome (MS) definition (biochemical and anthropometric indicators) on MS prevalence estimates in a population of overweight and mildly obese children.Design:Cross-sectional study.Subjects:Ninety-nine (64 girls) overweight or mildly obese, but otherwise healthy, pre-pubertal 6–9-year olds recruited for a randomized controlled trial of weight management.Measures:Height, weight and waist circumference were measured with BMI and waist z-scores calculated. Fasting cholesterol and fractions, glucose and insulin were measured, together with systolic and diastolic blood pressure (BP). Anthropometric and metabolic indicators were classified as normal or elevated using adult- or child-specific cut points with clustering of MS indicators also assessed using two adult and three child-specific definitions.Results:A total of 0–4% of subjects were classified with MS when adult definitions were applied. This increased to between 39 and 60% using child-specific definitions, varying according to whether hyperinsulinaemia was central to the MS classification. Systolic BP, triglycerides, total cholesterol, high-density lipoprotein cholesterol and waist z-score increased across insulin quartiles (P<0.05). The use of body mass index and waist circumference in the MS definition classified the same subjects.Conclusions:The classification of MS in children depends strongly on the definition chosen, with MS prevalence estimates higher if insulin is part of the definition and child-specific cut points for metabolic indicators are used. Hyperinsulinaemia and MS are common consequences of childhood obesity but they are not commonly part of the assessment or management plan for weight management in children. There is a need for the establishment of normal insulin ranges and consistent definition of MS in childhood and adolescence.

Effect of a low glycemic index compared with a conventional healthy diet on polycystic ovary syndrome

BACKGROUND Women with polycystic ovarian syndrome (PCOS) are intrinsically insulin resistant and have a high risk of cardiovascular disease and type 2 diabetes. Weight loss improves risk factors, but the optimal diet composition is unknown. Low-glycemic index (low-GI) diets are recommended without evidence of their clinical effectiveness. OBJECTIVE We compared changes in insulin sensitivity and clinical outcomes after similar weight losses after consumption of a low-GI diet compared with a conventional healthy diet in women with PCOS. DESIGN We assigned overweight and obese premenopausal women with PCOS (n = 96) to consume either an ad libitum low-GI diet or a macronutrient-matched healthy diet and followed the women for 12 mo or until they achieved a 7% weight loss. We compared changes in whole-body insulin sensitivity, which we assessed using the insulin sensitivity index derived from the oral-glucose-tolerance test (ISI(OGTT)); glucose tolerance; body composition; plasma lipids; reproductive hormones; health-related quality of life; and menstrual cycle regularity. RESULTS The attrition rate was high in both groups (49%). Among completers, ISI(OGTT) improved more with the low-GI diet than with the conventional healthy diet (mean +/- SEM: 2.2 +/- 0.7 compared with 0.7 +/- 0.6, respectively; P = 0.03). There was a significant diet-metformin interaction (P = 0.048), with greater improvement in ISI(OGTT) among women prescribed both metformin and the low-GI diet. Compared with women who consumed the conventional healthy diet, more women who consumed the low-GI diet showed improved menstrual cyclicity (95% compared with 63%, respectively; P = 0.03). Among the biochemical measures, only serum fibrinogen concentrations showed significant differences between diets (P < 0.05). CONCLUSION To the best of our knowledge, this study provides the first objective evidence to justify the use of low-GI diets in the management of PCOS.

A Parent-Led Family-Focused Treatment Program for Overweight Children Aged 5 to 9 Years: The PEACH RCT

OBJECTIVE: To evaluate a healthy lifestyle intervention to reduce adiposity in children aged 5 to 9 years and assess whether adding parenting skills training would enhance this effect. PARTICIPANTS AND METHODS: We conducted a single-blinded randomized controlled trial of prepubertal moderately obese (International Obesity Task Force cut points) children, aged 5 to 9 years. The 6-month program targeted parents as the agents of change for implementing family lifestyle changes. Only parents attended group sessions. We measured BMI and waist z scores and parenting constructs at baseline, 6, 12, 18, 24 months. RESULTS: Participants (n = 169; 56% girls) were randomized to a parenting skills plus healthy lifestyle group (n = 85) or a healthy lifestyle–only group (n = 84). At final 24-month assessment 52 and 54 children remained in the parenting skills plus healthy lifestyle and the healthy lifestyle–only groups respectively. There were reductions (P < .001) in BMI z score (0.26 [95% confidence interval: 0.22–0.30]) and waist z score (0.33 [95% confidence interval: 0.26–0.40]). There was a 10% reduction in z scores from baseline to 6 months that was maintained to 24 months with no additional intervention. Overall, there was no significant group effect. A similar pattern of initial improvement followed by stability was observed for parenting outcomes and no group effect. CONCLUSIONS: Using approaches that specifically target parent behavior, relative weight loss of ∼10% is achievable in moderately obese prepubertal children and can be maintained for 2 years from baseline. These results justify an investment in treatment as an effective secondary obesity-prevention strategy.

The relationship between obesity and hypoferraemia in adults: a systematic review

A growing number of studies suggest a potential link between obesity and altered iron metabolism. The purpose of this systematic review was to examine existing literature on iron status in obese populations. A comprehensive literature search was conducted. Included studies recruited participants ≥ 18 years with a body mass index ≥ 30 kg m−2 and provided descriptive statistics for haemoglobin or ferritin at a minimum. There were 25 studies meeting all eligibility criteria, of these 10 examined iron status in free‐living obese individuals and 15 reported baseline iron biomarkers from bariatric surgery candidates. Non‐obese comparison groups were used by 10 (40%) articles. In these, seven obese groups reported higher mean haemoglobin concentration; six reported significantly higher ferritin concentration; and four significantly lower transferrin saturation. Due to insufficient data, it was not possible to make conclusions regarding mean differences for soluble transferrin receptor (sTfR), hepcidin or C‐reactive protein. Existing evidence suggests a tendency for higher haemoglobin and ferritin concentration and lower transferrin saturation in obesity. Alternation of iron biomarkers in obese populations may be a result of obesity‐related inflammation and/or related comorbidities. Further research incorporating measurement of inflammatory cytokines, sTfR and hepcidin is required to confirm the impact of obesity on iron status.

Food, activity and family--environmental vs biochemical predictors of weight gain in children.

Objective: To identify whether measures of energy intake and expenditure predict excessive weight gain over time in children and to describe how these measures relate to similar measures in parents.Design: Prospective, descriptive study over 12 months with no intervention.Setting: University teaching hospital.Subjects: Children aged between 6.0 and 9.0 y. Recruitment was through advertisement. A total of 59 children (30 F), 41 mothers and 29 fathers. In all, 41 (69%) of the children were reviewed at 12 months (20 F).Results: No significant correlations were identified between body mass index (BMI) z-score change in children over 12 months for any dietary variable or for any measures of energy expenditure, including hours of television viewing or percent time spent in low-, moderate- or high-intensity activity. The BMI z-score change over 12 months was significantly correlated with LDL cholesterol and Apo B/ApoA-1 ratio, independent of percent body fat (r=0.45, P=0.01; r=0.37, P=0.03). A significant positive correlation was found for mothers and girls for percent time in moderate to high activity (r=0.44, P=0.03) and between fathers and children for percent time spent in low activity (r=0.43, P=0.005).Conclusions: The study has been unable to identify environmental predictors that indicate propensity to faster weight gain over time in this cohort of children, but has extended the evidence on lifestyle-influenced biochemical predictors that do. An overall lack of vigorous activity in this age group, and correlations between parental and child activity and inactivity have been identified.Sponsorship: The Australian Rotary Health Foundation, The Financial Markets Foundation for Children, The National Health and Medical Research Council.

Self-efficacy in relation to eating behaviour among obese and non-obese women

OBJECTIVE: To assess the effect of a 3 month behaviour modification weight management programme on self-efficacy and anthropometric variables among obese women seeking treatment at an obesity management clinic and to compare self-efficacy among these obese women to non-obese women.DESIGN: Cross sectional.SUBJECTS: A total of 161 non-obese (BMI 22.6±2.9 kg/m2) and 138 obese (BMI 37.7±5.8 kg/m2) women of similar age.MEASUREMENTS: Self-efficacy in relation to eating was assessed by the Weight Efficacy Lifestyle (WEL) questionnaire. Demographic information was obtained by interview and questionnaire in the obese and by questionnaire in the non-obese. Anthropometric measurements were obtained by direct measure in the obese and BMI was calculated from self-reported weight and height in the non-obese.RESULTS: At entry to the programme obese women scored significantly less (P<0.0001) than non-obese women on the WEL (99.4±34.1 vs 139.0±24.9). Women who completed the programme (n=65) demonstrated a decrease in waist circumference of 3.9±5.3 cm, a 10.0±11.5% loss of excess weight and a significant improvement in total WEL score from 106.0±30.3 to 126.5±28.4.CONCLUSION: Improvements in some dimensions of self-efficacy among obese women were of sufficient magnitude to attain scores similar to women of a normal weight. The WEL questionnaire may provide an additional measure of success as well as provide positive feedback and encouragement to the client.

Two-year outcomes of an adjunctive telephone coaching and electronic contact intervention for adolescent weight-loss maintenance: the Loozit randomized controlled trial

This paper reports the final 24-month outcomes of a randomized controlled trial evaluating the effect of additional therapeutic contact (ATC) as an adjunct to a community-based weight-management program for overweight and obese 13–16-year-olds. ATC involved telephone coaching or short-message-service and/or email communication once per fortnight. Adolescents were randomized to receive the Loozit group program—a two-phase behavioral lifestyle intervention with (n=73), or without (n=78), ATC in Phase 2. Adolescents/parents separately attended seven weekly group sessions (Phase 1), followed by quarterly adolescent sessions (Phase 2). Assessor-blinded, 24-month changes in anthropometry and metabolic health included primary outcomes body mass index (BMI) z-score and waist:height ratio (WHtR). Secondary outcomes were self-reported psychosocial and lifestyle changes. By 24 months, 17 adolescents had formally withdrawn. Relative to the Loozit program alone, ATC largely had no impact on outcomes. Secondary pre-post assessment of the Loozit group program showed mean (95% CI) reductions in BMI z-score (−0.13 (−0.20, −0.06)) and WHtR (−0.02 (−0.03, −0.01)) in both arms, with several metabolic and psychosocial improvements. Adjunctive ATC did not provide further benefits to the Loozit group program. We recommend that further work is needed to optimize technological support for adolescents in weight-loss maintenance. Australian New Zealand Clinical Trials Registry Number ACTRNO12606000175572.